A phase spacer is a long insulating bar which keeps apart two conductors of different phases at some point along the span between two adjacent pylons (generally one half or one third of the way along the span), and its function is to prevent two conductors of different phases from coming dangerously near to each other under the effect of large-amplitude oscillations or of electrodynamic forces due, for example, to a short circuit current.
A compensating arm is disposed between one phase and the earth of a metal support to hold a conductor or a strap back into position.
As for distance pieces, they are intended to keep apart conductors in a bundle of same phase conductors.
In these applications, it is very important for the insulator to be light so that its weight does not increase cable sag and in particular does not put a V shape into the catenary curve of a freely hanging conductor without spacers.
Further, to save weight, it has already been proposed that instead of using conventional insulators such as china or glass, an insulator of the type illustrated in FIG. 1 should be used. The main component of the insulator is a rod 1 made of glass fibres and resin with a vulcanized elastomer sheath 2 which has high resistance to cracking and to erosion by small electric arcs which may appear at the surface in particular under the effect of pollution. To increase the leakage path and to resist rainwater streaming along the surface, fins 3 made of an elastomer analogous to that which constitutes the sheath may be disposed along the sheath. Said elastomer is, for example, EPDM (Ethylene-Propylene-Diene Monomer).
The rod 1 generally has metal caps 4 fitted onto its ends by setting or crimping; a clip which holds a conductor 5 is fixed on the cap.
Preferred embodiments of the present invention lighten the preceding insulator, in particular at the conductor fixing device.